Incandescent body

ABSTRACT

An improved incandescent mantle formed of a woven fabric tube and having at least one open end with a fireproof attaching material provided for attaching at least one of the ends of the tube to a burner. At least one additional fireproof material portion is provided between the burner and mantle to reinforce and protect the mounted mantle from jarring forces.

FIELD OF THE INVENTION

The present invention relates to an incandescent body or mantlecomprising a fabric tube having at least one open end, with a fireproofattaching material provided for attaching the ends of the tube to aburner or to a shaped part for a burner of an incandescent lamp.

In addition, the present invention relates to a burner of anincandescent lamp having a rotationally symmetrical surface forattaching at least one end of an incandescent mantle.

BACKGROUND OF THE INVENTION

Such incandescent mantles comprise a circular knitted base material ofgenerally viscose mixed with metallic salts. The mantle is usuallyattached with a tie string, either directly onto a burner or else firston a prefabricated shaped part for the burner (the shaped part with theattached mantle is placed on the burner by the end user), and is thenburned off and brought to luminescence in the gas flame.

When this is done, the base material burns away completely, and all thatremains is the oxide skeleton of the metallic salts. Even slightmechanical stresses are sufficient to destroy it. If this oxide skeletonis subjected to jolts or vibrations, as for example during transportingor careless handling of the lamp, the mantle is usually destroyed at itsweakest point, namely at the burner.

To increase the mechanical stability of the mantle, the followingmethods are known in the prior art. One consists in reinforcing thefabric at the point of contact with the burner. To strengthen the oxideskeleton at its point of contact with the burner, the fabric is turnedinside out in the vicinity of the burner and chemically reinforced inthis area, so that it is doubled. The fabric and the oxide skeleton thatremain after combustion now comprise two layers, which are chemicallyreinforced. This two-layer oxide skeleton increases the time the mantleremains intact on the burner when subjected to jolts and impacts.

Another method consists in the choice of the tie string with which themantle is tied to the burner. To attach the mantle to the burner, athread is sewn into the fabric. In the usual attachment method, duringproduction a thread is threaded into the attachment opening or the twoattachment openings of the mantle with a greater or lesser number ofstitches; the end user then pulls the mantle onto a ceramic ring or anelongated one-piece or two-piece burner and draws the ends of the threadtight and ties them with a knot.

For other types of burners, the mantle is drawn in and pre-knottedalready during the production process, the diameter of the opening thatthus remains being specified to a precision of tenths of a millimeter.

The attaching material influences the durability of the mantle. The tiestring is the most widely used method of attaching the mantle worldwide.However, the selection of the tie string is subject to a variety ofcriteria. It must be resistant to high temperatures, should retaintextile properties even at high temperature and become neither hard norbrittle, and the knot must hold tightly. In addition to use of a tiestring, use of a metal clip instead of a tie string has also beenproposed.

REFERENCES CITED

U.S. Pat. No. 5,116,220 describes a round metal clip, matched to theshape of the burner but convenient for the consumer to handle, whichholds the mantle on the burner and is inserted through the fabric duringproduction, similar to the tie string. The convenience of use of thismetal clip is obtained at the cost of the stability of the mantle on theburner, which is less than that of the mantles attached by means of tiestring.

The metal clip described above was improved in U.S. Pat. No. 5,639,231,describing a similar metal clip but with a modified form, so that theoxide skeleton is no longer pressed onto the burner by the metal clip.The advantage compared to the metal clip indicated above consists in theimproved stability of the mantle on the burner, and the stabilityachieved is comparable to the stability of a mantle attached using tiestring.

THE OBJECTS OF THE INVENTION

The object of the present invention is to provide a mantle, or a burnerfor mantles, which exhibit increased stability of the mantle whensubjected to jolts and impacts, irrespective of the attaching materialsindicated above.

SUMMARY OF THE INVENTION

This object is fulfilled with a mantle comprising a fabric tube havingat least one open end, a fireproof attaching material being provided forattaching the ends of the tube to a burner or to a shaped part for aburner of an incandescent lamp, by providing at least one additionalfireproof material, preferably connected to the mantle, between theburner and the mantle at the at least one open end of the mantle and atleast on the side facing the burner or the shaped part for the burner,so that the mantle exhibits increased mechanical stability on the burneras a result.

In addition, the object is fulfilled in a burner of an incandescent lamphaving a rotationally symmetrical surface for attaching at least one endof a mantle, by the fact that the surface has a three-dimensionalmacroscopic structure. To test the mechanical stability of the mantle,the burned-off mantle together with the burner is attached to a joltingmachine and shaken until the mantle is damaged. The shaking time is themeasure of the mechanical resistance to jolts and impacts. The mantlesproduced in accordance with the present invention have increasedstability and service life, by a factor of more than three.

The mantle was also produced in accordance with the present inventionwith a round-shaped metal clip (U.S. Pat. No. 5,116,220) instead of thetie string. The produced mantle yielded more than 20 times the stabilityof the mantle equipped only with the metal clip.

When subjected to jolts, impacts and vibrations, the mantle inaccordance with the present invention wears out in an entirely differentmanner than conventional mantles. The conventional mantle is destroyedby the fact that the oxide skeleton becomes detached successively fromthe tie string, by jolting and other forces, until it is no longer heldby the latter and falls off of the burner. If the mantle produced inaccordance with the present invention is subjected to such jolts,impacts and vibrations, the oxide skeleton no longer becomes detachedfrom the tie string, and is held on the burner by the tie string for asignificantly longer period. The disclosed mantle herein is destroyedbeneath the attachment, namely in the mantle itself, so that thestability of this mantle depends only on the character of the oxideskeleton of which the mantle is made and on the shape of the burner.Thus, when the mantle is subjected to jolts, impacts and vibrations, theadditional fireproof material connected to the mantle thereby serves asa protective medium to separate the oxide skeleton from the attachingmaterial that functions as a tying medium, to protect it from theseforces. The present invention is based on the separation of these twofunctions. The protective medium can also assume the function of aspacer. A similar effect is also shown by the macroscopic structure ofthe burner surface.

Thus, in addition to the tying medium, an additional medium isincorporated into the mantle in the area of the burner. This protectivemedium may be incorporated for example as a thread, as follows:

-   -   a. it is incorporated into the fabric of the mantle with        stitches (similar to the way in which the tie string is stitched        in.)    -   b. it is incorporated loop-like around and through the fabric of        the mantle in the area of the opening. These may be multiple        loops that are incorporated continuously, but may also be        individual, separate loops placed at various locations around        the opening, each of which may be knotted separately.    -   c. it may be incorporated by being suspended only on the tying        medium on the inner side of the mantle in the area of the        burner, by means of a great variety of stitches (such as        buttonhole stitching.)    -   d. it is attached on the inner side of the mantle in the area of        the burner (for example by cementing or clipping.)    -   e. it is incorporated into the fabric of the mantle on the        knitting machine, at least in the area of the burner, in the        process of knitting the base material (usually viscose) of which        the mantle is made.

The thread may be, for example, a thread made up of a minimum proportionof high-temperature material and/or a fabric comprising a minimumproportion of high-temperature material, or a braided thread made up ofa minimum proportion of high-temperature material or knitted thread madeup of a minimum proportion of high-temperature material.

One advantageous embodiment of the present invention provides that theadditional fireproof material is in a crossing arrangement in at leastone location when the incandescent mantle is in the attached state. Thisachieves the advantageous result that the attaching material is kept ata distance at least at some points, namely at the crossing points.

Another advantageous and preferred embodiment of the present inventionprovides that the additional fireproof material is in the form of apreferably bead-like solid. The beads are strung onto the tie string onthe inside of the mantle when the tie string is threaded in, as a meansto limit contact with the burner so that at least in partial areas themantle is no longer in contact with the burner. It is then heldexclusively by the tie string. The mechanical explanation of theincreased stability is that in static terms the hold is no longer fixedbut a rotationally movable hold, so that no bending moments can beintroduced into the fabric by the holding point. But shaped parts thatare made up of metal, ceramic, porcelain or other high temperaturematerials are also conceivable as solid bodies. These shaped parts mayhave any form and design characteristics desired. These shaped parts areattached to the mantle in the area of the burner in such a way that theyfulfill a protective function for the mantle as described above.

In an alternative preferred embodiment of the present invention, thefireproof material of the protective body is structured in the form of aflexible body, preferably as a thread. In the production process such athread may be threaded or knitted into the fabric of the mantleespecially advantageously. When the tie string is pulled in to attachthe mantle to the burner, the thread forms loops, so that these areasact as a protective medium. A combination of tying medium and protectivemedium is also conceivable, connected to each other in such a way thatthe tying medium may be tightened and knotted more or less independentlyof the protective medium. One example of such a combination is a fabricin which a warp thread is distinguished by being used as a tie string.If such a fabric is stitched into the opening of the mantle like theclassic tie string, and if the warp thread which is distinguished as thetie string is drawn tight, the rest of the fabric remains in the openingand bunches up in such a way that it lies between the mantle and theburner. Another example is a tie string which is combined with aprotective thread (for example by enmeshing it) and is stitched in thearea of the opening of the mantle like the classic tie string in such away that the tie string may be tightened and knotted so that theprotective thread bunches together in the opening and lies between themantle and the burner.

At the same time, an advantageous refinement of the present inventionprovides for the thread to be passed loop-like through the fabric tubearound its circumference. The at least one loop or the loops do notnecessarily need to be present when the mantle is not attached, but maybe formed only during attachment of the mantle to the burner. The loopsalso do not have to be closed, but may also take the form, for example,of meander lines.

The formation of loops may be influenced in an advantageouslyreproducible way by routing the thread so that it encircles theattaching material, for example the tie string, in at least one place.

A further increase of stability is achievable by routing the thread sothat it encircles the end of the fabric tube. That results in the end ofthe fabric being reinforced at the same time by the loops that areformed. It is also possible to work in the tie string itself around oralong the opening of the mantle, after it has been sewn in around themantle by the usual method, so that it becomes a protective medium inthe second pass.

An advantageous refinement of the present invention provides for the tiestring to be routed so that it does not penetrate the fabric tube. Theresult is that the tie string no longer holds the mantle directly, butindirectly via the protective thread. Thus the thread is first sewn, forexample, into the mantle, and then the tie string is drawn through theloops of the thread that serves as a protective thread. That makes theholding of the mantle even more flexible. The mantle is held entirelyfree of the binding forces of the tie string.

To further increase the strength, provision may be made for the end ofthe fabric tube to be turned inside out. It is preferably turned inward,and the thread may be passed through one or both layers.

For production, to make it easier to recognize the areas that arestructured in accordance with the present invention, these may be dyedin the initially continuously knitted tube in such a way that the end ofthe fabric tube is dyed after it has been separated.

A further advantageous increase in service life is obtained if the endof the fabric tube is chemically reinforced, at least in the area of theprotective medium.

For the production process, a design is especially advantageous in whichthe thread and/or the tie string are incorporated into the fabric tubetransversely to the direction of knitting.

The mantles need to be modified only slightly in order to achieve theadvantages of the present invention, if the tie string penetrates thefabric tube at a distance from its end, and is attached to the fabrictube in such a way that it forms loops when it is tightened. With thisdesign it is possible to advantageously forego additional spacers orthreads. The tie string itself functions as the spacer through the loopsthat are formed. For example, the tie string itself, after it has beenstitched around the mantle in the usual way, is worked in again aroundor along the opening of the mantle, thus becoming a protective medium inthe second pass. Or alternatively, the tie string is not stitched inaround the mantle by the usual method. The tie string is stitched inaround the opening of the mantle so that in the area of the mantle thatfaces the burner, the string lies in between. It thus becomessimultaneously tying medium and protective medium.

An advantageous design of the burner provides for the surface to have athree-dimensional macroscopic structure, with the structure preferablybeing in the form of waves whose crests are oriented parallel to oneaxis of the rotationally symmetrical surface. This design is especiallyadvantageous in terms of the production technique.

Alternatively, the structure may be in the form of nubs.

BRIEF DESCRIPTION OF THE DRAWINGS

An example of the present invention is described on the basis of adrawing. The figures of the drawing show the following details:

FIG. 1 is a schematic side view of a mantle according to the presentinvention in the unattached state, according to a first exemplaryembodiment.

FIG. 2 is a top view of the end of a mantle according to the presentinvention, in accordance with FIG. 1.

FIG. 3 is a schematic side view of a mantle according to the presentinvention in the unattached state, according to a second exemplaryembodiment.

FIG. 4 is a top view of the end of a mantle according to the presentinvention, in accordance with FIG. 3.

FIG. 5 is a schematic side view of a mantle according to the presentinvention in the unattached state, according to a third exemplaryembodiment.

FIG. 6 is a top view of the end of a mantle according to the presentinvention, in accordance with FIG. 5.

FIG. 7 is a schematic side view of a mantle according to the presentinvention in the unattached state, according to a fourth exemplaryembodiment.

FIG. 8 is a top view of the end of a mantle according to the presentinvention, in accordance with FIG. 7.

FIG. 9 is a schematic side view of a mantle according to the presentinvention in the unattached state, according to a fifth exemplaryembodiment.

FIG. 10 is a schematic vertical section through a burner with the end ofa mantle attached to it.

FIG. 11 is a schematic vertical section through a burner with the end ofa mantle attached to it in a different manner.

FIG. 12 is a schematic vertical section through a burner with the end ofa mantle attached to a fabric on it.

FIG. 13 is a schematic vertical section through a burner with the end ofa mantle attached to a fabric on it in a different manner.

FIG. 14 is a schematic horizontal section through a surface of a burnerintended for attaching a mantle.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

In FIGS. 1 and 2, reference 1 designates the mantle, which is initiallyknitted continuously and has an open end 2 after a severing cut. At apreselected distance from end 2, a tie string 3 is drawn through thecircumference of the mantle in such a way that it is alternately on theinside and the outside. Bead-like fireproof bodies 4 are strung on thesections of tie string 3 that are on the inside. For this purpose, thesebodies have appropriate bores through which the tie string may bepassed. This arrangement is preferred.

FIGS. 3 and 4 show an alternative exemplary embodiment, in which athread 6 acts as a protective medium. As in the previously describedexample, the tie string is passed alternately through the mantle. In theareas 7 of string 3 that lie toward the inside, thread 6 is passedaround the latter in the form of a loop 8 and attached to tie string 3so that it can slide. The ends of thread 6 are affixed to the mantle bymeans of a knot 10. When tie string 3 is drawn tight, thread 6 formsloops 9. The formation of the loops 9 can be influenced reproducibly bythe routing and/or nature of the loops 8.

FIGS. 5 and 6 show an additional exemplary embodiment, in which thread6, which serves as a protective medium, is passed alternately throughmantle 1 at its upper end 2. When tie string 3 is drawn tight loops 9are formed, which encircle the end of mantle 1 in the manner of abuttonhole stitch. This type exhibits especially great durability.

FIGS. 7 and 8 represent a variant of the design according to FIGS. 5 and6. In contrast to FIGS. 5 and 6, the tie string is not passed throughmantle 1, but through the upper ends of loops 9 of thread 6, so thatmantle 1 is now attached to a burner indirectly through thread 6. Inaddition, means to reinforce the end 2 the mantle is provided by itbeing turned inside out, so that it is double-layered in the areabetween end 2 and cut edge 11. In addition, this area can also bechemically reinforced and/or dyed. The area that is turned inside outmay also be knitted of fireproof material, and may thus represent afabric 13 according to the present invention which assumes theprotective function.

FIG. 9 represents an exemplary embodiment in which the tie stringassumes both the protective function and the tying and holding function.To that end, tie string 3 is run twice around the circumference of themantle and is passed through it alternately a number of times. In thecourse of one pass around it is firmly connected to the mantle atseveral places 12, while in the course of the second pass around itpenetrates the mantle movably. When the tie string is drawn tight, ittherefore forms loops in the area with the attachment points 12.

The mantle that is processed by means of a protective medium in the areaof the burner according to the methods indicated above has significantlygreater stability when it is subjected to impacts, jolts and vibrations.Without major sacrifices of stability, as an alternative to thetraditional processing method, i.e. wrapping the mantle so that thefabric of the mantle is in two layers where it contacts the burner andsewing the tie string through both layers of fabric, the mantle producedin accordance with the present invention may be processed as follows:

-   -   a. The fabric of the mantle is turned inside out in the known        manner, but the tying medium is sewn through only one chosen        layer of the mantle fabric (depending on the nature of the        burner). This enables the sewing of the tying medium to be        performed more simply and more quickly.    -   b. The fabric of the mantle is not turned inside out, and the        tying medium is sewn through only one layer of mantle fabric.        The sewing of the tying medium can be performed more simply and        more quickly.    -   c. The tying medium can be introduced more simply, more quickly        and with perfect regularity, by incorporating the tying medium        on the knitting machine in the process of knitting the base        material (usually viscose) of which the mantle is made, and        transversely to the direction of knitting, at the place that is        attached to the burner. This tying medium, which is included in        the knitting, is also subjected to the further processing of the        knit goods, without exception, until the mantle is completed.        The tying medium which is thus included in the knitting can be        handled in the same way as the tie string that is sewn in the        traditional manner with more or fewer stitches, in order to        attach the mantles to the burner.

In FIG. 10, the two threads provided in the form of fireproof material 5are sewn only into the inner fabric of the mantle facing the burner, andtie string 3 is sewn through both layers of fabric. After the mantle isattached to the burner, the fireproof material is drawn up but is nottied, so that it lies slack in the fabric. In FIG. 11, the threads inthe form of a fireproof material 5 are attached to the burner with acement that burns up completely in the heat, and the mantle is attachedto the burner only with the tie string. The fireproof material has thusbeen connected neither to the mantle nor to the burner. Surprisingly,both embodiments showed outstanding stability in tests.

FIG. 12 shows a mantle with a fireproof fabric 13 on the inside, whichis attached to the mantle with tie string 3, and FIG. 13 shows the caseof a fabric applied to the burner and a mantle tied to it. Theseembodiments also do not differ in their outstanding stability in tests.

Finally, FIG. 14 shows a schematically represented horizontal sectionthrough a surface 14 of a burner 16, which is intended for attachment ofa mantle. The surface has a macroscopic structure 15 in the form of nubsand/or waves.

1. An incandescent mantle comprising a woven fabric tube having at leastone open end, with a fireproof attaching material provided for attachingthe ends of the tube to a burner or to a shaped part for a burner of anincandescent lamp, wherein at the at least one open end of the mantleand at least on the side facing the burner or the shaped part for theburner at least one additional fireproof material, preferably connectedwith the mantle, is provided between the burner and mantle, and themantle has increased mechanical stability with respect to the burner asa result.
 2. The incandescent mantle according to claim 1, wherein theadditional fireproof material is in a crossing arrangement in at leastone location when the incandescent mantle is in the attached state. 3.The incandescent mantle according to claim 2, wherein the additionalfireproof material is in the form of a preferably bead-like solid. 4.The incandescent mantle according to claim 2 or 3, wherein theadditional fireproof material is in the form of a flexible body,preferably as a thread.
 5. The incandescent mantle according to claim 2,3 or 4, wherein the at least one thread in the attached state is passedaround the circumference of the fabric tube in at least one location,forming a loop.
 6. The incandescent mantle according to one or more ofthe preceding claims, wherein the thread is routed so that it windsaround the attaching material in at least one place, preferably windingaround the inside.
 7. The incandescent mantle according to one or moreof the preceding claims, wherein the thread is routed so that it windsaround the end of the fabric tube.
 8. The incandescent mantle accordingto one or more of the preceding claims, wherein the attaching materialis routed so that it does not penetrate the fabric tube.
 9. Theincandescent mantle according to one or more of the preceding claims,wherein the fireproof material is a woven fabric that preferably isattached to the incandescent mantle by means of the attaching material.10. The incandescent mantle according to one or more of the precedingclaims, wherein the end of the fabric tube is turned inside out.
 11. Theincandescent mantle according to one or more of the preceding claims,wherein the end of the fabric tube is dyed.
 12. The incandescent mantleaccording to one or more of the preceding claims, wherein the end of thefabric tube is chemically reinforced at least in the area of theattaching material.
 13. The incandescent mantle according to one or moreof the preceding claims, wherein the string and/or the attachingmaterial, if it is in the form of a thread, is introduced into thefabric tube during the knitting, transversely to the direction ofknitting.
 14. A burner of an incandescent lamp, having a rotationallysymmetrical surface for attaching at least one end of an incandescentmantle, wherein the surface has a three-dimensional macroscopicstructure.
 15. The burner according to claim 14, wherein the structureis in the form of waves, whose crests are oriented parallel to one axisof the rotationally symmetrical surface.
 16. The burner according toclaim 14, wherein the structure is in the form of nubs.